The present invention relates to a sulfonated rubber composition, a process of preparing such composition, and a process of using such composition.
During oil field applications such as drilling and completion operations, large flow channels such as, for example, fractures, joints, and voids around the wellbore, whether induced or natural, can cause various problems during such drilling and completion operations. Such problems can include a substantial loss of fluids from the wellbore which can result in the loss of hydrostatic head with the subsequent potential for losing control of the well. Such problems can also lead to damage of the production capacity of oil and gas zones when the flow channels represent a portion of the drainage pattern.
Various methods have been used in an attempt to control the loss of fluids from the flow channels. For example, one common method is to increase the viscosity of the fluids, such as drilling muds, or to increase the resistance of the flow of such fluids into the formation. Another technique involves the addition of a bulk material, such as cork, saw dust, paper, mica flakes, cloth fibers, and the like and combinations thereof, to such fluids being used. However, these methods are not always effective because the solids may be lost in the flow channels. Further, addition of such bulk materials does not assure the plugging of such channels.
Another example method utilized to reduce or eliminate lost circulation during oil field applications such as drilling and completion operations is to use a cement, such as Plaster of Paris or a silicate, either alone or in combination with the previously discussed bulk materials. However, problems are often encountered using the cement such as the cement separating out of the cement slurry that is introduced into the wellbore, heavier cement particles in the slurry having a tendency to separate from the water and become dehydrated before the porous subterranean formation is sealed, and the cement slurry passing into the porous formation without effectively plugging the openings in the wellbore sidewall.
Another such process which has been utilized to prevent the loss of fluids during oil field applications is to employ a gel. Such use of a gel can result in the crosslinking of such gel either at the surface, during placement, or in-situ. However, hydraulic forces may lead to dehydration, channeling, or even extrusion of such gel. Further, it is difficult to control the gelation characteristics of water-soluble polymers and therefore difficult to assure reduction of lost circulation of fluids during oil field applications.
Similarly, fractures can also occur in an injection well, a producing well, or both. In order to correct sweep profile encountered in fractured reservoirs, large volumes of gelable polymer solutions can be used to plug the fractures. However, the effectiveness of these treatments are adversely affected by hydraulic failure of the gel near the wellbore.
In addition, during the drilling of wells, drilling fluid is generally circulated down the drill string and back up the annulus between the drill string and the wellbore face. A casing string or liner is then cemented into the wellbore. However, numerous annular leaks through the cement can occur. Such oil or gas leaks through the cement contaminate the ground water causing environmental problems. Further, gas leaks through the cement out to the well surface can also present a hazardous condition.
Thus, there is a continuing need to develop an effective and efficient method of reducing or eliminating lost circulation of fluids used during oil field applications. Further, development of an effective and efficient composition and process for using such composition for oil field applications, such as reducing or eliminating lost circulation of fluids used during such oil field applications, would be a significant contribution to the art and to the economy.
In addition, with the rapid increase of the number of automobiles, a severe problem has occurred in connection with the disposal of rubber compositions such as waste tires. Thus, development of a method to dispose of rubber compositions such as waste tires would also be a significant contribution to the art and to the economy. Further, development of a method to dispose of rubber compositions such as waste tires which results in a composition which can be used for oil field applications, such as for reducing or eliminating lost circulation of fluids used during such oil field applications, would also be a significant contribution to the art and to the economy. Still further, development of a method to dispose of rubber compositions such as waste tires which results in a composition which can be used for contacting with asphalt, i.e., used as an additive in or for asphalt, would also be a significant contribution to the art and to the economy.
An object of the present invention is to provide a sulfonated, oxidized rubber composition.
Another object of the present invention is to provide a neutralized, sulfonated, oxidized rubber composition.
Still another object of the present invention is to provide a composition comprising a sulfonated, oxidized rubber composition which is useful for contacting with asphalt, i.e., useful as an additive in or for asphalt.
Yet another object of the present invention is to provide a composition comprising a neutralized, sulfonated, oxidized rubber composition which is useful for a variety of processes including, but not limited to, use for oil field applications such as preventing the loss of fluids used during such oil field applications.
Still another object of the present invention is to provide a method(s) of making a sulfonated, oxidized rubber composition, a composition comprising such sulfonated, oxidized rubber composition, a neutralized, sulfonated, oxidized rubber composition, and a composition comprising such neutralized, sulfonated, oxidized rubber composition.
Still yet another object of the present invention is to provide a process of using rubber compositions, such as waste tires, to provide a sulfonated, oxidized rubber composition, a composition comprising such sulfonated, oxidized rubber composition, a neutralized, sulfonated, oxidized rubber composition, and/or a composition comprising such neutralized, sulfonated, oxidized rubber composition.
A further object of the present invention is to provide a process of disposing of rubber compositions, such as waste tires, in a process that is economically cheaper and easier than prior art methods.
A still further object of the present invention is to provide a process for preventing the loss of fluids used during oil field applications such as preventing seepage losses of such fluids and reducing fluid loss in water-based fluids and emulsions used during such oil field applications.
According to an embodiment of the present invention, a sulfonated, oxidized rubber composition is provided which can be used as an additive in or for asphalt. Such sulfonated, oxidized rubber composition is prepared by a process which comprises contacting a quantity of a rubber composition, which is of a particle size generally in the range of about 150 micrometers to about 2000 micrometers, with an oxidizing agent to provide an oxidized rubber composition. Such oxidized rubber composition is then contacted with a sulfur-containing acid to provide a sulfonated, oxidized rubber composition which is then subjected to cooling and, optionally, subjected to drying. Preferably, such sulfonated, oxidized rubber composition is contained in a suspension comprising such sulfonated, oxidized rubber composition and sulfur-containing acid to provide a composition comprising such sulfonated, oxidized rubber composition which can be contacted with asphalt, i.e., used as an additive in or for asphalt.
According to another embodiment of the present invention, a neutralized, sulfonated, oxidized rubber composition is provided which can be used for oil field applications, such as preventing the loss of fluids used during such oil field applications. Such neutralized, sulfonated, oxidized rubber composition is prepared by a process which comprises contacting a quantity of a rubber composition, which is of a particle size generally in the range of about 150 micrometers to about 2000 micrometers, with an oxidizing agent to provide an oxidized rubber composition. Such oxidized rubber composition is then contacted with a sulfur-containing acid to provide a sulfonated, oxidized rubber composition which is then subjected to cooling and contacting with a base to provide a neutralized, sulfonated, oxidized rubber composition which is then subjected to drying and, optionally, size reduction. Such neutralized, sulfonated, oxidized rubber composition may be contacted with other materials including, but not limited to, an aqueous medium, and one or more other components such as clays, polymers, other loss circulation additives, and the like and combinations thereof, to provide a composition comprising a neutralized, sulfonated, oxidized rubber composition which can be used for oil field applications such as preventing the loss of fluids used during such oil field applications.
According to another embodiment of the present invention, a process which can be used for oil field applications, such as preventing the loss of fluids used during such oil field applications, is provided. The process comprises contacting a neutralized, sulfonated, oxidized rubber composition, preferably a composition comprising such neutralized, sulfonated, oxidized rubber composition, with a subterranean formation wherein such neutralized, sulfonated, oxidized rubber composition, preferably a composition comprising such neutralized, sulfonated, oxidized rubber composition, can be the same as that disclosed herein.
The term xe2x80x9chydrocarbonxe2x80x9d refers to any hydrocarbon(s) which may or may not be oxygenated or substituted with appropriate substituents.
The term xe2x80x9coil field applicationxe2x80x9d refers to, but is not limited to, any drilling, completion of drilling, production of hydrocarbons, permeability alteration, water coding correction, water shutoff, gas shutoff, zone abandonment, and the like and combinations thereof.
The term xe2x80x9cfluidxe2x80x9d refers to any fluid used for or during oil field applications. Examples of suitable fluids include, but are not limited to, drilling fluids, completion fluids, work-over fluids, and the like and combinations thereof.
The term xe2x80x9crubberxe2x80x9d refers to one or more of a group of synthetic elastomers and thermoplastic rubbers having properties similar to natural rubber. Examples of rubber include, but are not limited to, butyl rubber (such as the copolymer of isobutylene and isoprene), polychloroprene, sodium rubber, acrylonitrilebutadiene copolymers, butadiene-styrene copolymers, ethylenepropylene-diene rubber, polyisoprene, polyacrylonitrile, silicone, epichlorohydrin, polyurethane, and the like and combinations thereof. A preferred rubber is butyl rubber which is commonly found in waste tires.
The term xe2x80x9coxidizing agentxe2x80x9d refers to any compound that spontaneously evolves oxygen either at room temperature or under slight heating. Examples of suitable oxidizing agents include, but are not limited to, peroxides, chlorates, perchlorates, nitrates, permanganates, oxygen under pressure, and the like and combinations thereof. A preferred oxidizing agent is hydrogen peroxide.
The term xe2x80x9coxidizedxe2x80x9d refers to any mixture or composition disclosed herein which has been contacted with an oxidizing agent as disclosed herein according to a process of the present invention.
The term xe2x80x9csulfonatedxe2x80x9d refers to any mixture or composition disclosed herein which has been contacted with a sulfur-containing acid as disclosed herein according to a process of the present invention.
The term xe2x80x9cneutralizedxe2x80x9d refers to any mixture or composition disclosed herein which has been contacted with a base as disclosed herein according to a process of the present invention.
The term xe2x80x9casphaltxe2x80x9d refers to any asphalt composition, preferably semi-solid, known in the art including, but not limited to, petroleum asphalt, Trinidad pitch, mineral pitch, cut-back asphalt, and the like and combinations thereof which is obtained primarily from the residue or bottoms of the petroleum refining industry having bitumens as primary constituents and can be used primarily for road paving, road coating, and roofing.
According to an embodiment of the present invention, a sulfonated, oxidized rubber composition which can be used for contacting with asphalt, i.e., used as an additive in or for asphalt, is provided. Such sulfonated, oxidized rubber composition can be neutralized to provide a neutralized, sulfonated, oxidized rubber composition which can be used for oil field applications. The neutralized, sulfonated, oxidized rubber composition of the present invention can also be referred to as a salt of a sulfonated, oxidized rubber composition. A process of producing a sulfonated, oxidized rubber composition of the present invention comprises contacting, preferably by mixing or stirring, a rubber composition with an oxidizing agent, preferably hydrogen peroxide, under an oxidizing agent-contacting condition to provide an oxidized rubber composition. Such rubber composition has a particle size generally in the range of from about 150 micrometers to about 2000 micrometers, preferably in the range of from about 150 micrometers to about 850 micrometers, more preferably in the range of from about 250 micrometers to about 850 micrometers, and most preferably in the range of from 300 micrometers to 600 micrometers.
Such rubber composition is preferably a butyl rubber in the form of waste tires which have been subjected to particle size reduction by any manner or method(s) known in the art to obtain a particle size disclosed herein and then subjected to any cryogenic process known in the art to freeze such tires making them brittle and easily pulverized. Many of the means for reducing the size of the rubber composition, preferably butyl rubber in the form of waste tires, such as granulating means or grinding means or crushing means, suitable for use in a process of the present invention are described in detail in Perry""s Chemical Engineers"" Handbook, Sixth Edition, at pages 8-20 through 8-48, which pages are incorporated herein by reference. Thus, suitable means for reducing, such as grinding means, granulating means, or crushing means can include, but are not limited to, devices such as crushers, mills, shredders, cutters, and the like.
The amount of oxidizing agent required is an amount which, when used according to a process of the present invention, provides for an oxidized rubber composition. The amount of oxidizing agent required is an amount which provides for a weight ratio of rubber composition to oxidizing agent generally in the range of from about 1:2 to about 30:1, preferably in the range of from about 1:1 to about 15:1, and more preferably in the range of from 2:1 to 10:1.
The oxidizing agent-contacting condition comprises a temperature sufficient to maintain a reaction between the rubber composition and the oxidizing agent. Generally, the temperature is in the range of from about 70xc2x0 F. to about 120xc2x0 F., preferably in the range of from about 70xc2x0 F. to about 115xc2x0 F., and more preferably in the range of from 70xc2x0 F. to 110xc2x0 F. The oxidizing agent-contacting condition also comprises a pressure in the range of from about atmospheric (i.e., about 14.7 pounds per square inch absolute) to about 100 pounds per square inch absolute (psia), preferably about atmospheric, and a time period sufficient to allow the temperature to be maintained. Generally such time period is in the range of from about 1 minute to about 60 minutes, preferably in the range of from about 1 minute to about 30 minutes, and more preferably in the range of from 5 minutes to 20 minutes. If the temperature ranges for the oxidizing agent-contacting condition cannot be obtained from and/or maintained with the exothermic nature of the reaction of the oxidizing agent with the rubber composition, then additional heat can be applied to such mixture by any manner or method(s) known in the art such as a hot plate, bunsen burner, and the like and combinations thereof.
The resulting oxidized rubber composition is then subjected to contacting, preferably by mixing or stirring, with a sulfur-containing acid under an acid-contacting condition to provide a sulfonated, oxidized rubber composition, preferably a sulfonated, oxidized butyl rubber. Examples of suitable sulfur-containing acids include, but are not limited to, sulfuric acid, fuming sulfuric acid, chlorosulfonic acid, p-toluene sulfonic acid, methane sulfonic acid, and the like and combinations thereof. The presently preferred sulfur-containing acid is sulfuric acid. In addition, a first aqueous medium, such as deionized water, can be added to the mixture comprising a rubber composition and oxidizing agent before contact with a sulfur-containing acid. The amount of such aqueous medium, if added, can generally be in the range of from about 10 percent to about 90 percent of the total volume of the mixture comprising a rubber composition and an oxidizing agent, preferably in the range of from about 15 percent to about 85 percent of the total volume of the mixture comprising a rubber composition and an oxidizing agent, and more preferably in the range of from 20 percent to 80 percent of the total volume of the mixture comprising a rubber composition and an oxidizing agent.
Generally, the concentration of sulfur-containing acid, preferably sulfuric acid, can be in the range of from about 0.01 molar (molar refers to a concentration in which 1 molecular weight in grams (1 mole) of a substance is dissolved in enough solvent to make 1 liter of solution) to about 15 molar, preferably in the range of from about 0.02 molar to about 10 molar, more preferably in the range of from about 0.05 molar to about 8 molar, and most preferably in the range of from 0.1 molar to 6 molar.
The amount of sulfur-containing acid required is an amount which, when used according to a process of the present invention, provides for a sulfonated, oxidized rubber composition. The amount of sulfur-containing acid required is an amount that provides for a mixture, comprising an oxidized rubber composition, a sulfur-containing acid, and optionally a first aqueous medium, having a pH generally in the range of from about 2 to about 6, preferably in the range of from about 2.5 to about 5.5, and more preferably in the range of from 3 to 5.
The acid-contacting condition comprises a temperature based on the exothermic nature of the reaction of the sulfur-containing acid with the mixture comprising an oxidized rubber composition and optionally a first aqueous medium. Generally such temperature is in the range of from about 110xc2x0 F. to about 300xc2x0 F., preferably in the range of from about 110xc2x0 F. to about 290xc2x0 F., and more preferably in the range of from 120xc2x0 F. to 280xc2x0 F. Such acid-contacting condition also comprises a pressure in the range of from about atmospheric (i.e., about 14.7 pounds per square inch absolute) to about 100 pounds per square inch absolute (psia), preferably about atmospheric, and a time period sufficient to allow the temperature to be maintained. Generally such time period is in the range of from about 1 minute to about 60 minutes, preferably in the range of from about 1 minute to about 30 minutes, and more preferably in the range of from 5 minutes to 20 minutes. If the temperature ranges for the acid-contacting condition cannot be obtained from and/or maintained with the exothermic nature of the reaction of the sulfur-containing acid with the mixture comprising an oxidized rubber composition and optionally a first aqueous medium, then additional heat can be applied to such mixture by any manner or method(s) known in the art such as a hot plate, bunsen burner, and the like and combinations thereof.
The resulting mixture, also referred to as a suspension, can then be subjected to cooling under a cooling condition sufficient to provide a cooled mixture having a temperature in the range of from about 60xc2x0 F. to about 150xc2x0 F., preferably in the range of from about 60xc2x0 F. to about 140xc2x0 F., and more preferably in the range of from 70xc2x0 F. to 130xc2x0 F. Such cooling condition comprises a pressure in the range of from about atmospheric (i.e., about 14.7 pounds per square inch absolute) to about 100 psia, preferably about atmospheric, and a time period necessary to maintain such temperature. Generally, such time period is in the range of from about 1 minute to about 60 minutes, preferably in the range of from about 1 minute to about 30 minutes, and more preferably in the range of from 1 minute to 20 minutes. Such cooling can be accomplished by any manner or method(s) known in the art.
Optionally, the resulting cooled mixture can be dried under a drying condition sufficient to provide a dried, sulfonated, oxidized rubber composition, preferably a dried, sulfonated, oxidized butyl rubber. Generally, such drying condition comprises a temperature in the range of from about 180xc2x0 F. to about 280xc2x0 F., preferably in the range of from about 200xc2x0 F. to about 260xc2x0 F., and more preferably in the range of from 200xc2x0 F. to 250xc2x0 F. Such drying condition can also comprise a time period sufficient for drying such mixture generally in the range of from about 0.1 hour to about 40 hours, preferably in the range of from about 0.1 hour to about 20 hours, and more preferably in the range of from 0.1 hour to 10 hours to provide a dried, sulfonated, oxidized rubber composition. Such drying condition can also include a pressure generally in the range of from about atmospheric (i.e., about 14.7 pounds per square inch absolute) to about 150 psia, preferably in the range of from about atmospheric to about 100 psia, more preferably about atmospheric, so long as the desired temperature can be maintained. Any drying method(s) known to one skilled in the art such as, for example, air drying, heat drying, and the like and combinations thereof can be used.
Preferably, a sulfonated, oxidized rubber composition of the present invention is present as a component of a liquid suspension comprising such sulfonated, oxidized rubber composition, a sulfur-containing acid, and, optionally, a first aqueous medium. The formation of such suspension allows such suspension to be used for contacting with asphalt, i.e., used as an additive in or for asphalt. When a sulfonated, oxidized rubber composition of the present invention is present as a component of such liquid suspension, the weight ratio of liquid comprising a sulfur-containing acid and, optionally, a first aqueous medium to a sulfonated, oxidized rubber composition of the present invention is a weight ratio which allows such liquid suspension to be contacted with asphalt, i.e., to be used as an additive in or for asphalt. Generally, such weight ratio is in the range of from about 1:1 to about 50:1, preferably in the range of from about 5:1 to about 40:1, and more preferably in the range of from 110:1 to 20:1. The liquid suspension comprising such sulfonated, oxidized rubber composition, a sulfur-containing acid, and, optionally, a first aqueous medium has a pH generally in the range of from about 2 to about 6.5, preferably in the range of from about 2.5 to about 6, and more preferably in the range of from 3 to 6.
To produce a neutralized, sulfonated, oxidized rubber composition of the present invention, the resulting mixture comprising a sulfonated, oxidized rubber composition, preferably a cooled mixture, can then be subjected to contacting with a base under a base-contacting condition sufficient to provide a neutralized, sulfonated, oxidized rubber composition, preferably a neutralized, sulfonated, oxidized butyl rubber, which can also be referred to as a salt of a sulfonated, oxidized rubber composition, preferably a salt of a sulfonated, oxidized butyl rubber. In addition, a second aqueous medium, such as deionized water, can be added to the mixture comprising a sulfonated, oxidized rubber composition before such contacting with a base. The amount of such second aqueous medium if added can generally be in the range of from about 10 percent to about 90 percent of the total volume of mixture, preferably in the range of from about 15 percent to about 85 percent of the total volume of mixture, and more preferably in the range of from 20 percent to 80 percent of the total volume of mixture.
Examples of a suitable base include, but are not limited to, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetramethylammonium bisulfide, tetraethylammonium bisulfide, lithium hydroxide, sodium hydroxide, sodium hydrosulfide, sodium bisulfide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, sodium bicarbonate, sodium carbonate, sodium oxide, sodium sulfide, magnesium oxide, calcium oxide, calcium carbonate, sodium phenoxide, barium phenoxide, calcium phenoxide, and the like and combinations thereof. The preferred base is sodium hydroxide.
Generally, the concentration of base, preferably sodium hydroxide, can be in the range of from about 0.01 molar (molar refers to a concentration in which 1 molecular weight in grams (1 mole) of a substance is dissolved in enough solvent to make 1 liter of solution) to about 15 molar, preferably in the range of from about 0.02 molar to about 10 molar, more preferably in the range of from about 0.05 molar to about 8 molar, and most preferably in the range of from 0.1 molar to 6 molar.
The amount of base required is an amount which, when used according to a process of the present invention, provides for a neutralized, sulfonated, oxidized rubber composition. The amount of base required is an amount that provides for a mixture, comprising a sulfonated, oxidized rubber composition, a base, and optionally a second aqueous medium, having a pH generally in the range of from about 6 to about 11.5, preferably in the range of from about 7 to about 11, and more preferably in the range of from 7.5 to 10.
The base-contacting condition comprises a temperature that provides a neutralized, sulfonated, oxidized rubber composition, preferably a neutralized, sulfonated, oxidized butyl rubber. Generally, such temperature is in the range of from about 100xc2x0 F. to about 200xc2x0 F., preferably in the range of from about 100xc2x0 F. to about 190xc2x0 F., and more preferably in the range of from 110xc2x0 F. to 180xc2x0 F. Such base-contacting condition also comprises a pressure in the range of from about atmospheric (i.e., about 14.7 pounds per square inch absolute) to about 100 psia, preferably about atmospheric, and a time period sufficient to provide a neutralized, sulfonated, oxidized rubber composition generally in the range of from about 1 minute to about 60 minutes, preferably in the range of from about 1 minute to about 30 minutes, and more preferably in the range of from 5 minutes to 20 minutes. After contacting with a base, the resulting mixture can be subjected to cooling under a cooling condition as described herein to provide a cooled mixture. Such cooling allows for easier handling of the mixture.
Optionally, the mixture, preferably cooled mixture, can then subjected to drying under a drying condition sufficient to provide a dried, neutralized, sulfonated, oxidized rubber composition, preferably a dried, neutralized, sulfonated, oxidized butyl rubber. Generally, such drying condition comprises a temperature in the range of from about 180xc2x0 F. to about 280xc2x0 F., preferably in the range of from about 200xc2x0 F. to about 260xc2x0 F., and more preferably in the range of from 200xc2x0 F. to 250xc2x0 F. Such drying condition can also comprise a time period sufficient for drying such mixture generally in the range of from about 0.1 hour to about 40 hours, preferably in the range of from about 0.1 hour to about 20 hours, and more preferably in the range of from 0.1 hour to 10 hours to provide a dried, neutralized, sulfonated, oxidized rubber composition. Such drying condition can also include a pressure generally in the range of from about atmospheric (i.e., about 14.7 pounds per square inch absolute) to about 150 psia, preferably in the range of from about atmospheric to about 100 psia, more preferably about atmospheric, so long as the desired temperature can be maintained. Any drying method(s) known to one skilled in the art such as, for example, air drying, heat drying, and the like and combinations thereof can be used.
Generally, a sulfonated, oxidized rubber composition of the present invention has a particle size which enables such sulfonated, oxidized rubber composition to be used according to a process of the present invention as an additive in or for asphalt. Generally, a sulfonated, oxidized rubber composition of the present invention has a particle size in the range of from about 150 micrometers to about 2000 micrometers, preferably in the range of from about 150 micrometers to about 850 micrometers, more preferably in the range of from about 250 micrometers to about 850 micrometers, and most preferably in the range of from 300 micrometers to 600 micrometers.
Generally, a neutralized, sulfonated, oxidized rubber composition of the present invention has a particle size which enables such neutralized, sulfonated, oxidized rubber composition to be used according to a process of the present invention for oil field applications such as preventing the loss of fluids used during such oil field applications. Generally, a neutralized, sulfonated, oxidized rubber composition of the present invention, preferably a dried, neutralized, sulfonated, oxidized rubber composition of the present invention, has a particle size in the range of from about 150 micrometers to about 2000 micrometers, preferably in the range of from about 150 micrometers to about 850 micrometers, more preferably in the range of from about 250 micrometers to about 850 micrometers, and most preferably in the range of from 300 micrometers to 600 micrometers.
If necessary, a sulfonated oxidized rubber composition of the present invention can be subjected to particle size reduction by any manner or method(s) known in the art to obtain a sulfonated, oxidized rubber composition of the present invention having a particle size as disclosed herein. Such size reduction can include, but is not limited to, grinding, crushing, granulating and the like and combinations thereof, of the sulfonated, oxidized rubber composition to provide a material having the critical physical properties, such as particle size, necessary for use as an additive in or for asphalt.
A neutralized, sulfonated, oxidized rubber composition of the present invention, preferably a dried, neutralized, sulfonated, oxidized rubber composition of the present invention, can be subjected to particle size reduction by any manner or method(s) known in the art to obtain a neutralized, sulfonated, oxidized rubber composition of the present invention having a particle size as disclosed herein. Such size reduction can include, but is not limited to, grinding, crushing, granulating and the like and combinations thereof, of the neutralized, sulfonated, oxidized rubber composition to provide a material having the critical physical properties, such as particle size, necessary for use for oil field applications such as preventing the loss of fluids used during such oil field applications.
Any suitable means for reducing the size of a sulfonated, oxidized rubber composition of the present invention and/or a neutralized, sulfonated, oxidized rubber composition of the present invention can be used to obtain a particle size as disclosed herein. Many of the means for reducing the size of the sulfonated, oxidized rubber composition and/or neutralized, sulfonated, oxidized rubber composition, such as granulating means or grinding means or crushing means, suitable for use in a process of the present invention are described in detail in Perry""s Chemical Engineers"" Handbook, Sixth Edition, at pages 8-20 through 8-48, which pages are incorporated herein by reference. Thus, suitable means for reducing, such as grinding means, granulating means, or crushing means can include, but are not limited to, devices such as crushers, mills, shredders, cutters, and the like. The preferred means for reducing the particle size of a neutralized, sulfonated, oxidized rubber composition of the present invention includes mills.
Generally, a sulfonated, oxidized rubber composition of the present invention can have any suitable particle shape that allows such sulfonated, oxidized rubber composition to be used as an additive in or for asphalt. Examples of a suitable particle shape of a sulfonated, oxidized rubber composition of the present invention include, but are not limited to, irregularly-shaped particles, pellets, and the like and combinations thereof.
Generally, a neutralized, sulfonated, oxidized rubber composition of the present invention can have any suitable particle shape that allows such neutralized, sulfonated, oxidized rubber composition to be used for oil field applications such as preventing the loss of fluids used during such oil field applications. Examples of a suitable particle shape of a neutralized, sulfonated, oxidized rubber composition of the present invention include, but are not limited to, irregularly-shaped particles, pellets, and the like and combinations thereof.
According to another embodiment of the present invention, a neutralized, sulfonated, oxidized rubber composition of the present invention, preferably a composition comprising such neutralized, sulfonated, oxidized rubber composition of the present invention, is contacted with a subterranean formation, preferably by injection into such subterranean formation. A neutralized, sulfonated, oxidized rubber composition of the present invention can be combined or mixed, by any suitable manner or method(s) known in the art, with an aqueous medium, a suspension comprising undissolved solids, gas, or oil, and the like and combinations thereof, before it is contacted with, preferably injected into, a subterranean formation.
Preferably, a neutralized, sulfonated, oxidized rubber composition of the present invention can be combined or mixed, by any manner or method(s) known in the art, with any suitable aqueous medium, such as water, to provide an aqueous solution comprising such neutralized, sulfonated, oxidized rubber composition suitable for contacting with, preferably injecting into, a subterranean formation wherein such aqueous solution comprising such neutralized, sulfonated, oxidized rubber composition is capable of flowing or traveling to a desired location in such subterranean formation. When an aqueous medium is present, the weight ratio of aqueous medium to a neutralized, sulfonated, oxidized rubber composition of the present invention is generally in the range of from about 1:1 to about 50:1, preferably in the range of from about 5:1 to about 40:1, and more preferably in the range of from 10:1 to 20:1.
In addition to an aqueous medium, a neutralized, sulfonated, oxidized rubber composition of the present invention can be combined or mixed, by any manner or method(s) known in the art, with one or more other components such as clays, polymers, other loss circulation additives, and the like and combinations thereof. Examples of suitable clays include, but are not limited to, montmorillonite, kaolinite, halloysite, vermiculite, attapulgite, smectite, illite, saconite, sepiolite, polygorskite, fuller""s earth, chlorite, and the like and combinations thereof. Examples of suitable polymers include, but are not limited to, starches, gums, biopolysaccharides, cellulose, ethers, synthetics, and the like and combinations thereof. A preferred polymer is a carboxylate-containing polymer which can be crosslinked with a multivalent metallic compound. Examples of suitable other loss circulation additives include, but are not limited to, paper, cork, saw dust, wood shavings, rock, mica flakes, cloth, cements (such as Plaster of Paris), silicates, and the like and combinations thereof. The amount of such additional component(s) to be added to a neutralized, sulfonated, oxidized rubber composition of the present invention, and preferably an aqueous medium, can be any amount which provides for a composition comprising a neutralized, sulfonated, oxidized rubber composition of the present invention which can be contacted with, preferably injected into, a subterranean formation and preferably helps prevent the loss of fluids into such subterranean formation during oil field applications. A preferred composition comprises a neutralized, sulfonated, oxidized rubber composition of the present invention, an aqueous medium, and a clay.
When an additional component(s) is present, the weight ratio of additional component(s), such as clays, polymers, other loss circulation additives, and the like and combinations thereof, to a neutralized, sulfonated, oxidized rubber composition of the present invention, and preferably an aqueous medium, is generally in the range of from about 1:1 to about 50:1, preferably in the range of from about 5:1 to about 40:1, and more preferably in the range of from 10:1 to 20:1.
The amount of a neutralized, sulfonated, oxidized rubber composition of the present invention, preferably a composition comprising such neutralized, sulfonated, oxidized rubber composition of the present invention, contacted with, preferably injected into, a subterranenan formation according to a process of the present invention, can vary widely depending on the treatment required or desired. Generally, a process of contacting, preferably injecting, a neutralized, sulfonated, oxidized rubber composition of the present invention, preferably a composition comprising such neutralized, sulfonated, oxidized rubber composition of the present invention, with or into a subterranean formation is carried out when, for example, there is an indication of fluid loss during oil field applications; or when there is an increase in fluid or gas pressure in the drill stem for treating an unstable matrix in a subterranean formation; or there is an increase in unconsolidated sediments as shown by a higher rate of unconsolidated sediment reduction; and/or the like and combinations thereof.
The nature of the subterranean formation is not critical to the practice of a process of the present invention. A neutralized, sulfonated, oxidized rubber composition of the present invention, preferably a composition comprising such neutralized, sulfonated, oxidized rubber composition of the present invention, can be contacted with, preferably injected into, a subterranean formation having a temperature generally in the range of from about 35xc2x0 F. to about 600xc2x0 F., preferably in the range of from about 50xc2x0 F. to about 550xc2x0 F., and more preferably in the range of from 60xc2x0 F. to 500xc2x0 F. Any manner or method(s) known to one skilled in the art such as, for example, pumps, can be used for contacting, preferably injecting, a neutralized, sulfonated, oxidized rubber composition of the present invention, preferably a composition comprising such neutralized, sulfonated, oxidized rubber composition of the present invention, with or into a subterranean formation.
Before contact with, preferably before injection into, a subterranean formation, the temperature of a neutralized, sulfonated, oxidized rubber composition of the present invention, preferably a composition comprising such neutralized, sulfonated, oxidized rubber composition of the present invention, is generally in the range of from about 30xc2x0 F. to about 150xc2x0 F., preferably in the range of from about 40xc2x0 F. to about 120xc2x0 F., and more preferably in the range of from 50xc2x0 F. to 100xc2x0 F.
The following examples are presented to further illustrate this invention and are not to be construed as unduly limiting the scope of this invention.